The image sensor is a device capable of converting a light signal into an electrical signal, which is widely applied in various electronic devices such as cameras, mobile phones equipped with cameras and the like. A composite image sensor refers to an image sensor integrated with a device capable of sensing a plurality of light waves and capable of identifying various light wave images thereof. For example, a composite image sensor integrated with a device is capable of sensing an infrared light and a visible light, and is capable of identifying the infrared light and the visible light of an infrared light image as well as a visible light image.
Since the composite image sensor is integrated with the multi-light wave sensing function, and has a small device size, the composite image sensor is particularly important and practical in the field of image sensors. For example, a composite image sensor integrated with the function of sensing an infrared light and a visible light is capable of implementing applications such as face recognition, fingerprint recognition, iris recognition and the like based on the capture of the infrared light signal. Additionally, the composite image sensor may be associated with applications such as environmental photographing, auxiliary recognition and the like based on capture of the visible light signal.